With only a month to go, the $484 million California Academy of Sciences building hardly appears ready for anything - living, stuffed or pickled - and certainly not for the thousands of visitors expected on opening day.

"But the stage is set, and right now, today, we plan to have everything up and running in just four weeks - everything," insisted Christopher Andrews, director of the academy's public programs, whose main job right now is keeping tabs on the bewildering complexity that marks every final installation between now and the opening.

With just 31 days to go, Andrews and the academy's entire crew of scientists and other assorted employees have their work cut out for them.

Tanagers, honeycreepers, finches and their ilk flew freely for the first time Tuesday amid the towering trees of the new rain forest inside the academy in Golden Gate Park.

But in Costa Rica, hundreds of infant butterflies due at the academy are still in their cocoons, being readied for a plane flight to the same rain forest. They'll fly amid the forest's 70-foot-high trees soon after entomologists from the U.S. Department of Agriculture give the academy final approval next week for them to migrate here.

In other parts of the academy's immense green-roofed building, workers in the African Hall - reconstructed almost exactly as it was 80 years ago - are still installing specialized new lights to make the eyes of zebras, antelopes and the old stuffed gorilla sparkle as if they were alive.

The animal exhibits of life and evolution in Madagascar and the Galapagos Islands are still largely in crates.

Astronomically sophisticated computer operators are still testing software for the planetarium's unique new star projectors, which will reveal the changing heavens as never before. And everywhere, on all four floors of the new academy, crates are still being unpacked, mobile cranes are scurrying, carpenters are hammering, floors are being scrubbed and scrubbed again.

Waiting for move

Back at 875 Howard St. in downtown San Francisco - where the academy and its temporarily truncated exhibits kept the show running in miniature during four years of exile - hundreds of living fish, birds, insects, reptiles and amphibians are awaiting the crosstown transfer to the commodious naturalistic habitats they'll move into any day now.

Soon to be transferred to the new academy building, too, are legions of bats, flying geckos, chameleons, ants by the thousands and many more animals and plants.

Some are already there and happy. Sharks and rays are frolicking above the sandy bottom of their tank, and the penguins are completely at home and pairing up - boy with girl - in their rock-rimmed pool. The newly arrived alligators are safely installed in their swamp, where they slither around far more actively than the two that habitually lay torpid in a far-less-attractive habitat at the old academy's aquarium so many years ago.

The newly built Philippine coral reef - at 25 feet, the deepest artificial reef of any museum in the world - is alive with fish, and the amazingly diverse corals, reared from infancy at the academy's farm on Howard Street, are growing more colorful day by day.

Nearby, the rocky reef in the aquarium typical of the Farallones is filled with the same varied species of fish that live around any underwater crag off coastal Northern California.

Hundreds of fish

And some 1,700 fish are contentedly swimming in the varied waters of the academy's Steinhart Aquarium. "We'll have at least 2,500 by opening day," Andrews said, "and more than 4,000 within a year."

Meanwhile, interactive screens that kids will surely take to - reared as they are these days on video games - are everywhere. In the exhibit on Madagascar's weird and wonderful life, for example, Andrews himself maneuvered a handheld net on the screen to capture 78 different species of swift-flying insects - a striking lesson in biodiversity.

"It's all about celebrating life because that's the academy's mission and passion - to show through every exhibit and program how science and evolution are fundamental to understanding the amazing biological diversity of our world and what we can do to save it," he said.